Three years can be a surprisingly long time. In the space of three years things can change a huge deal, and it shows upon reflection. Battlefield Heroes has reached its three year anniversary today, and it seems much more recent. The game was EA's first entry into the free to play (F2P) market, though it was followed with Battlefield Play4Free, which is also still available. Heroes is more notable though for its drastic differences from the rest of the franchise. While the franchise was always famous for its realistic visuals and more tactical gameplay, Heroes differed.
Instead, it was a cartoon shooter with a WWII flavor. In some ways you could almost compare it to Team Fortress 2; both games were free-to-play, trying to avoid the grittier, more realistic designs of other games in the same market. The game, while free-to-play, does also allow players to pay real-world cash to unlock items. Again, like many other games with a similar business model it has received complaints about being "pay-to-win", though Heroes tends to leave the playing field fairly even regardless of whether someone has paid for an item or not. The game never explicitly refers to Nazis or Nazism, preferring instead to allude to them instead with their faction naming. The two factions are the 'National Army' and 'Royal Army', ostensibly the British Army and Wehrmacht forces.
The day of public release is also very well known in the world of music, for a reason you more than likely already know. It was on this day, three years ago, that Michael Jackson was confirmed to have died at his mansion in Los Angeles. For this reason the game's release date is always going to be very memorable, due to the large scale media attention focused upon Michael Jackson's death at this point as well. The coincidence, while insignificant, makes the release date much more easily remembered.